This invention relates generally to breastmilk pumps, and particularly to breast pumps for use in the expression of mother""s milk which include a pump mechanism which can be manually driven, such as a piston pump.
Pumps used to extract or express mother""s milk are well known. Breastmilk pumps are adapted to massage the breast to relieve it of its contents of milk, such as for storage in a container for later use by an infant.
Breast pumps typically come in two basic types: those that are driven off of a motor, such as an electric motor-driven vacuum source connected to the milk extraction device, as by tubing, and those that are driven by hand, that is, manual pumps. See Medela, Inc. U.S. Pat. Nos. 4,857,051, 4,929,229, 4,964,851, 5,007,899 and 5,071,403, for example, as to the state of the art. These breast pumps ordinarily include a funnelshaped rigid hood, or shield, which is placed over the nipple and a substantial portion of the breast for milk extraction. Actuating the vacuum pump intermittently generates a reduced pressure or vacuum within the shield to create a suction which draws the nipple and adjacent breast further into the narrower portion of the shield. This pulling action both massages and constricts the breast in a manner reminiscent of suckling, resulting in the expression of milk into the funnel opening of the shield. The milk then typically flows into a collecting chamber or container for storage for later use or disposal.
The means generally used for generating the intermittent suction within the shield in a manually driven pump may be a compressible bulb or preferably a pneumatic piston pump. The latter commonly would include a piston cylinder that is connected to the shield, with a piston mounted for reciprocating movement within the piston cylinder, such as under the driving action of a hand-driven piston rod connected at one end to the piston, with the other end extending out of the rear of the piston cylinder. Further details regarding a breast pump with such a manually driven piston pump can be gleaned from the aforementioned U.S. Pat. Nos. 4,875,051 and 5,007,899, for example.
The manually driven breast pump described above has many advantages, such as its relatively compact nature and its operability without an electric power source, enabling it to be readily transported and used anywhere. There are times, however, where transportation of the breast pump and power requirements are not significant factors, such as in the home or in a hospital environment. In those instances, it can be desirable to use some other means to drive the breast pump. Dispensing with the need to manually operate the breast pump frees one of the user""s hands; this would allow the pumping of both breasts simultaneously using two breast pump assemblies, considerably speeding up the extraction process.
Disclosed in U.S. Pat. No. 5,007,899 to Larsson, and sold by Medela, Inc. under the name LACTINA, is a motorized drive which can accept the Medela, Inc. manually driven piston pump without modification of the piston pump. The LACTINA motorized drive operates the otherwise manual piston pump, freeing the hands of the mother. Another advantage attendant to the LACTINA motor drive for the manual pump is the ability to isolate the milk extraction equipment, and specifically the piston pump, from the inner workings of the motor drive. The relatively inexpensive manual pump components can thereby become essentially disposable, or at least provided so that each mother of a plurality of women using a single motor drive, as in a hospital environment, will have her own piston pump. Hygienic use of the motor drive is thus enhanced, and the risk of cross-contamination is virtually eliminated.
The ability to readily switch a piston pump between a manual mode and a motor driven mode in the foregoing manner is obviously quite advantageous. A motorized breast pump, however, still requires an electrical supply such as batteries or a wall outlet. The motorized breast pump of necessity can also be somewhat heavy and large, to accommodate the electric motor and drive train.
A manual breast pump that can be actuated by foot instead of by hand offers a general solution to the problems explained above while simultaneously retaining the inherent advantages of the two types of pumps. Currently, there are no foot actuated breast pumps on the market. U.S. Pat. No. 5,304,129 issued Apr. 19, 1994, to Suzanne Forgach describes a breast pump that utilizes a treadle and platform combination to provide a means for operation by foot. However, there are many problems with this design. Such an apparatus is bulky and cumbersome. It requires an awkward motion that does not utilize the larger muscle groups in the legs. It does not provide a sucking action that closely resembles the infant""s, which has been shown to provide the most effective means of milk expression. There is no way of cleaning this pump which invariably becomes contaminated over time because of the vapors from the warm milk. Additionally, this prior art does not isolate the milk reservoir from the pump, and therefore it requires a relatively large displacement pump or bellows which further increases the bulk of this device.
The present invention has as a principal objective to provide a foot drive which can readily and removably accept an otherwise manually operated breast pump, so that the manual pumping elements will be mechanically driven by the foot of the user to generate an alternating negative pressure for milk extraction. Accordingly, the present invention provides an improved breast pump assembly which includes such an otherwise manually operable breast pump in a first mode of operation, which in a second mode of operation is attachable to a foot pedal device adapted to readily receive and then mechanically drive the otherwise hand-drivable pump to effect the expression of mother""s milk.
In a third mode of operation, the otherwise manually operable pump can be attached to a LACTINA motor drive to drive the piston pump. The foot powered breast pump of the invention has the advantage of freeing at least one of the user""s hands to allow the pumping of both breasts simultaneously or performing other tasks during the pumping process, without the need for a source of electricity to drive a motor. The foot powered breast pump of the present invention is easy to use, and durably constructed. Mechanically operating the breast pump with the larger muscles of the leg reduces fatigue and is also more relaxing for the user.
Another objective of the present invention is to provide for a novel foot actuated breast pump with a lightweight structure which is also simple and inexpensive to manufacture. A particularly noteworthy advantage of the present invention is the capability of the device to store in a compact and protective manner when not in use.
Still another object of the present invention is to provide a simple means for adjusting the maximum amount of suction or negative pressure generated with each pump stroke.
Yet another object of the present invention is to provide a simple means of disassembly of the device for cleaning and/or for conversion to a very portable hand operated breast pump.
To these additional ends, another embodiment has a flexible tubular line that is disconnected and the housing is held in a compact closed position by a locking latch or bail at the end opposite the hinge. The tubular line may optionally be stored within the closed housing.
For transportation and storage purposes it is desirable that the suction device be as compact as possible. Therefore, in the preferred embodiment there are one-way valves located between the funnel shaped receiving members and the collection chambers. The purpose of these valves is to isolate the collection chambers from the receiving members when a vacuum or negative pressure is applied. This enables the, full force of the reciprocating pump to be applied to the receiving members, which allows the volume of the pump to be substantially smaller than would be the case if the collection chambers were not isolated. It will be noted that these valves also offer other advantages such as minimizing the amount of milk vapor that can enter the tubular lines and allowing the collection chambers to consist of plastic bags or liners, since these volumes are no longer affected by the periodic negative pressure. There is furthermore disclosed a means for providing adjustment of the vacuum produced by the device.